I need to create users to let them access folders in my computer. But People I need to give access doesn't want to give me their computer login password (it's needed to avoid the username/password insert every time). I can let them in?

You create a "default" password for a user and they log in with that password, and they can change the password, after logging in with the password you provided, to their favorite password. The new user never has to provide you with their password.